Y-type clevis yoke for electric power transmission lines



Sept. 16, 1969 E. H. wARGo 3,467,295

Y-'TYPE CLEVIS YOKE FOR ELECTRIC POWER TRANSMISSION LINES Filed sept. 29, 196':

United States Patent O U.S. Cl. 174-144 5 Claims ABSTRACT OF THE DISCLOSURE A yoke for separatingly supporting a plurality of lbundled conductor clamps from suspension insulators has integral clevises formed therein for receiving and corona shielding bent bolts and eyebolt fittings for connecting the yoke to the conductor clamps or the the insulators or both.

This invention relates to electric power transmission lines and more particularly to yokes for separating a plurality of bundled conductors and supporting them from suspension insulators.

In the evolution of electric power transmission lines the voltage has progressively increased which caused increasingly severe problems in controlling corona formation. This led to the use of bundled conductors in which by properly selecting conductors in bundled arrangements, ycontrol of lcorona formation could be realized. This in turn led to the use of yokes for maintaining the bundled configuration where the conductors are supported from suspension insulators. Usually there are separate fittings for attaching the insulators to the yoke and for attaching the yoke to the conductor clamps.

It is desirable that the total length of all this hardware be as short as possible so as to utilize to the maximum extent the inherent corona shielding effect of the conductor bundle on the hardware. It is also desirable that the hardware have articulated joints `approximating those of a universal joint so as to accommodate longitudinal motion due to conductor galloping and lateral motion d-ue to conductor sway, this being particularly important where insulator V-strings or the equivalent are used as they restrain free swinging movement of their lower ends. It is also desirable that unavoidable frictional Wear due to motion in the articulated joints be confined as much as possible to the relatively low cost easily replaceable attachment fittings rather than to the more costly and harder to replace yoke.

In accordance with this invention, the yoke has an integrally formed recessed clevis or shackle for receiving both an attachment fitting in the form of an eyebolt and an interconnecting bent bolt. In this manner, the length is shortened, wear is concentrated on the engaging surfaces of the eyebolt fitting and the bent bolt both of which are of low cost and easily replaceable, corona shielding of the ends of the bent bolt is facilitated, and there is more freedom of motion of the fittings than in conventional arrangements.

An object of the invention is to provide a new and improved yoke for coupling to insulator or conductor clamp attachment fittings or both.

Another object of the invention is to provide a bundled conductor yoke for electric power transmission lines having integral recessed clevises for receiving an eyebolt attachment fitting.

The invention Will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Patented Sept. I6, 1969 ICC In the drawing,

FIGURE 1 is a perspective view of an embodiment of the invention,

FIGURE 2 is a transverse sectional view taken on line 2-2 of FIG. l,

FIGURE 3 is a similar view taken on line 3 3 of FIG. 1, and

FIGURE 4 is a fragmentary side elevation View partly in phantom showing a particular condition of operation of the invention shown in FIG. 1.

Referring now to the drawing and more particularly to FIG. 1, there -is shown therein a yoke indicated generally at 1 which is in the form of a comparatively fiat plate or beam 2 of any suitable structural material. lt may have a number of openings 3 for reducing its weight or cost or both. Its upper edge is provided with an integral transverse flange 4 extending on both sides and rounded so as to act as an integral corona shield. The bottom edge at the ends is bifurcated and flared at 5 with the legs or tines perforated at 6 as shown more clearly in FIG. 2 so as to receive a bent bolt 7 having a retaining nut 8 and cotter key 9. This construction forms an integral recessed Y-type clevis by which an eyebolt fitting 10 can be attached for articulated movement by passing the bent bolt 7 through the holes 6 and the eye of the eyebolt 10. Each fitting 10 may and usually will support a saddle clamp 11 for one of a bundle of transmission line conductors 12.

The upper edge of the yoke beam 2 is also provided with `bifurcatedly flared symmetrically located portions forming integral recessed portions 13 whose ared sides 14, as shown more clearly in FIG. 3, are perforated to receive another bent bolt 16 with its retaining nut 17 and cotter key 18. Thus there is provided a corona shielded short length articulated attachment to a suspension insulator connecting fitting 19 to which a suspension insulator 2) is pivotally connected. It should be understood that the left-hand recess 13 with its eyebolt 16 is similarly attached to an insulator which in this case is in the configuration of V-strings.

The recesses 13' are provided with drain passageways 21 extending downwardly from near their bottom through the yoke beam 2 to one of the holes 3.

FIG. 4 illustrates another feature of the invention involving positioning the outer edge of each recess 13 to constitute a stop 22 which limits the outward pivotal motion of the connecting fitting 19 when its associated insulator string is slack so as to prevent the lowermost skirt or petticoat 23 of insulation from contacting or banging 4against the casting 2.

Slack in the V-strings is usually caused by a sidewise wind load on the transmission line which will produce slack in the leeward string. Another cause of slack is during construction before the conductor bundle is hung from the yoke. In this case, both V-strings will be slack. Such slackness results in their having a more or less catenary curve instead of being essentially straight as they are under normal full gravity load.

It will be noted that each of the four integral clevises is a so-called Y-type clevis in which the central part is formed by the yoke plate proper and the flaring or bifurcated parts are formed by the sides of the recesses.

It will also be noted that the above described construction permits the fittings 10 and 19 not only to rotate about their eyebolts but also to move or swing in a transverse plane so as to provide essentially universal joint coupling or attachment.

It will also be noted that the ends of the bent bolts including their cotter keys are effectively corona shielded by either the top flange 4 or by the flaring of the sides 14 of the recesses 13.

It will also be noted that practically all of the wear due to swinging of the fittings and 19 will occur on the bent bolts essentially at their centers or at least where the eyes `of the ttings 10 and 19 engage the bent bolts. Inasmuch as these parts are relatively inexpensive and are easily replaceable this construction is a very economical one to maintain especially as the bent bolts can easily be removed under hot line conditions.

It should, of course, be understood that the invention is not limited to use with insulator V-strings and is not limited to the use with a two conductor bundle. Accordingly, therefore, I wish to have it understood that I intend herein to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A conductor yoke for electric power transmission lines comprising, in combination, a plate member extending in a plane and being solid between opposite exterior surfaces generally parallel to said plane and having upper and lower edges, portions of said plate member adjacent said edges being bifurcated so as to form clevis arms spaced on opposite sides of said plane and defining an opening extending inwardly from the respective edge, each bifurcated portion having a transverse perforation passing therethrough and opening on opposite sides of said plate member, and bolt means passing through said perforation and across said opening of each bifurcated portion and having retaining means on opposite ends engaging the opposite exterior surfaces of said plate member.

2. A device as defined in claim 1, wherein the bifurcated portion at the upper edge of said plate member forms a cup-shaped clevis opening, the latter clevis opening being separated and spaced from the clevis opening at the lower edge.

3. A device as defined in claim 2, wherein two said cup-shaped clevis openings are formed spaced from each other in the upper edge of said plate member, and two clevis openings are provided spaced from each other in the lower edge of said plate member.

4. A device as defined in Aclaim 1, said upper edge of said plate member being formed at said clevis opening therein with stop means for preventing contact with said plate member of the lowermost insulator of an insulator string connected within said clevis opening.

5. A device as defined in claim 1, said upper edge having a' rounded flange on each side for providing corona shielding.

References Cited UNITED STATES PATENTS 1,173,642 2/1916 Belcher 248-63 X 1,375,974 4/1921 Pierce et al. 174-150 1,903,024 3/ 1933 Brock 248-63 3,076,863 2/ 1963 Lantz et al 174-149 X 3,240,870 3/ 1966 Harmon 174-149 3,250,852 5/1966 Hollander 174-144 3,260,795 7/ 1966 Bethea 174-144 3,266,826 8/1966 Bethea 174-150 X FOREIGN PATENTS 629,187 7/ 1927 France.

OTHER REFERENCES German printed application 1,132,207, Riebl, June 28, 1962.

LARAMIE E. ASKIN, Primary Examiner U.S. Cl. X.R. 174-149; 248-58 

